Apparatus for controlling the flow of water to boilers



J. A. DOBLE.

APPARATUS FOR CONTROLLING THE FLOW OF WATER To BOILERS.

APPLI CAI ION FILED MAY 15, 1918.

Patented July 25, 1922.

INVENTOR.

WITNESS A TTORNE Y5 UNITED STATES PATENT OFFICE.

JOHN A. DOBLE, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO DOBLE LABORA-TORIES, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

APPARATUS FOR CONTROLLING THE FLOW'OF WATER TO BOILERS.

Specification of Letters Patent.

Patented July 25, 1922.

Application filed May 15, 1918, Serial No. 234,769.

controlling the flow of water to boilers inaccordance with temperatureconditions within the boiler, and especially to boilers provided with acontinuously driven feed,

water pump.

An object of the inventionis to provide means for stopping thesupply offeed water to the boiler when the temperature therein reaches apredetermined minimum and for starting the supply of feed water whenthetemperature reaches a predetermined maximum.

A further object of the invention is to control the flow of feed waterto the boiler without producing an excessive pressure in the feed waterline.

The invention possesses other advantageous features, some of which, withthe foregoing, will be set forth at length in the following descriptionwhere I shall outline in full, that form of the invention which I- haveselected for illustration in the drawing accompanying and forming partof the present specificatlon. In said drawing I have shown one form ofthe apparatus of my invention, but it is to be understood that I do notlimit myself to such form, since the invention, as expressed in theclaims, may be embodied in a plurality of forms. The drawing is a partlydiagrammatic representation of the apparatus of my invention.

The apparatus of my invention is particularly applicable for use onsteam propelled automobiles or trucks, where it is desirable that theflow of feed water to the boiler or steam generator be automaticallycontrolled 1 to maintain a substantially constant temperature within theboiler. The feed water is drawn from the supply tank 2 by the pump 3 andis forced through the pipe 4 into the boiler 5, the pipe 4 beingprovided with a check valve 6 to prevent a reverse flow of the feedwater. The pump is usually connected to the steam engine or to therunning gear of the vehicle so that it is continually in operation whenthe vehicle is in motion. The amount of steam consumed by the enginevaries with difference in load, roadbed and conditions of tralfic andwith this varying steam consumption, means must be provided forcontrolling the supply of feed water to the boiler. The capacity of thepum-p, if'operated continuously'duringthe operation of the engine,

is in excess of the requirements of the boiler,

so that under the heaviest conditions of operation it can be relied uponto provide sufficient feed water. lVith smaller steam consumption, theamount of feed water introduced into the boiler would be in excess ofthe requirements and the boiler would soon become cold due to the excessof water. In accordance with my invention I provide means for startingand stopping the supply of feed water to the boiler when certainpredetermined maximum and minimum temperatures are reached within theboiler, thereby maintaining the proper amount of water in the boiler.

Connected to the pipe 4, between the pum 3 and the check valve fi, is aby-pass conduit 7 which is connected at its other end to the supply tank2- and means areprovided for opening and closing the by-pass inaccordance with variations in temperature within the boiler. Arranged inthe by-pass conduit, is a shell 8, made of brass or other non-magneticmaterial and fixed in the shell and in tight contact therewith is a core9 of iron or steel having a passage 12 therethrough in communicationwith the by-pass conduit, so that the by-passed water passes through thepassage. The lower end of the core 9 is finished smooth so that it formsa valve seat. Arranged in the shell below the core is an iron or steelplunger or valve 13 having a solidcenter portion and a ribbed or groovedperiphery, the longitudinal grooves 14 forming passages for the water.The shell is closed at the bottom by a nipple 15 and the nipple or theplunger are so constructed that the grooves 14 are always incommunication with the passage 16 in the nipple. In the presentconstruction the lower face of the plunger is provided with a pluralityof spaced projections 17 which hold the body of the plunger above thenipple. Surrounding the shell 8 is a solenoid 18, which when energized,causes the plunger to rise and seat against the lower end of the core 9and prevent the fiow of water through the core.

\Vhen the plunger is in its lower position, the by-pass is open and thepumped water passes from the pump to the supply tank and When theplunger is raised, the by-pass is closed and the pumped water passesinto the boiler.

Means are provided for opening and closing the solenoid circuit inaccordance with temperature conditions within the boiler. Arranged inthe solenoid circuit is a battery 21, a hand operated switch 22 and atemperature operated switch 23. The temperature operated switchcomprises a resilient flexible element 24 fixed at one end and engagingat its other end, a lever 25 which is operated by an expansible metallicrod 26 extending into the boiler. As the length of the rod varies, thelever is moved to vary the fiexure of the element 24 and thereby openand close the solenoid circuit. An increase in temperature to apredetermined degree causes the solenoid circuit to he closed, closingthe by-pass and causing the Water to be pumped into the boiler and thesubsequent lowering of boiler temperature causes the solenoid circuitand the by-pass to be opened, stopping the flow of water to the boiler.

1. An apparatus for controlling the temperature within a steam generatorcomprising means for introducing a liquid into the generator and aby-pass for the liquid, characterized by the fact that the by-pass isopened or closed solely by variations in the temperature of the steamwhereby this temperature is kept within definite limits.

2. In an apparatus for controlling the temperature within a steamgenerator, means forintroducing a liquid into the generator, means forbypassing the liquid and means controlling the latter means arranged topermit the entr of liquid at a definite temperature and to prevent entryof the liquid at a lower temperature.

3. In an apparatus for controlling the temperature within a steamgenerator. 2 liquid supply tank. means for drawing liquid from the tankand for forcing it into the generator, a by-pass for the li( uid forallowing it to re-enter the tank. and means for entirely opening andentirelv closing the by-pass, this means being responsive solely totemperature of the steam and so arranged that the by-pass is opened whenthe steam 5 has a relatively low temperature and closed for a highertemperature.

In testimony whereof. I have hereunto set my hand at San Francisco.(ali'lorniziu this 2nd day of May, 1918.

JOHN A. DOBLE.

In presence of- H. G. Paosr.

